Preshaped thin-walled dental trays and methods of manufacturing and using such trays

ABSTRACT

Pre-shaped, non-custom dental trays are either preloaded with a dental treatment composition (e.g., in the form of a gel) or filled with a dental treatment composition just prior to placement over a person&#39;s teeth. The pre-shaped dental tray is thin and flexible, which allows it to be placed over a person&#39;s teeth and then approximately conform to the person&#39;s teeth. The pre-shaped, non-custom dental trays can therefore perform similar to a customized tray but without having to go through the more lengthy customization procedure. According to one embodiment, a pre-shaped dental tray can be pre-loaded with a dental treatment composition and stored within a sealed packaging container. Alternatively, it can be sold by itself or in combination with a treatment composition that a user can load into the dental tray. The tray can be manufactured by vacuum forming polymeric sheet material over a template.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/701,788, filed Nov. 4, 2003, now U.S. Pat. No. 6,964,571 which is acontinuation-in-part of U.S. application Ser. No. 10/350,629, filed Jan.24, 2003. now U.S. Pat. No. 7,004,756. The disclosures of the foregoingapplications are incorporated in their entirety.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention is in the field of dental trays used to provide adesired dental treatment to a person's teeth. More particularly, theinvention relates to pre-shaped, non-custom dental trays that are usefulin applying a dental treatment composition to a person's teeth (e.g., adental bleaching composition).

2. The Relevant Technology

Virtually all people desire white or whiter teeth. To achieve this goal,people either a have veneers placed over their teeth or have their teethchemically bleached. In the past, patients who desired to have theirteeth bleached had to submit to conventional in-office bleachingtechniques. The process generally involves: (1) making an alginateimpression of the patient's teeth; (2) making a stone cast or model ofthe impression; (3) vacuum forming a dental tray from the model, usuallyfrom a heated sheet of thin ethyl vinyl acetate (EVA) material, and (4)trimming to exclude gingival coverage. This method results in a traythat is soft and flexible, that is customized to very accurately fitover the patient's teeth, and that is therefore very comfortable towear. However, the process for making a customized tray is timeconsuming, often taking days or weeks before the customized tray isavailable to the patient, and the resulting tray is quite expensive.

Because of the time and cost associated with customized trays, lesscostly alternatives have been developed, but these alternatives havesubstantial disadvantages in terms of accuracy, effectiveness, andcomfort.

One alternative is the so-called “boil and bite” tray. A relativelythick, non-custom preformed tray (similar to a mouth guard) made of EVAor polyethylene or other material is submerged in boiling water. Thepreformed tray is relatively thick (e.g., >2 mm) to prevent the trayfrom collapsing on itself and becoming entirely unusable during theheating process. Upon removal from the heated water, the tray is quicklyplaced inside the patient's mouth. The patient quickly bites down andapplies contact pressure to make an impression of the biting surfaces ofthe user's teeth. One problem with “boil and bite” trays is that theyare relatively thick and bulky, which make them more intrusive and lesscomfortable to wear compared to customized trays. The thickness oflarge, bulky preformed trays also limits the accuracy with which theycan conform to the user's teeth and/or gums and makes the trays morerigid.

To the extent that boil and bite trays made from EVA and like materialsare made with thinner walls, such trays are extremely difficult to workwith because they tend to shrivel and collapse outside extremely narrowwindows of temperature and heating time. For example, if left in a hotwater bath too long (i.e., for more than a few seconds) they can quicklybecome limp and lose their pre-form shape, making it difficult orimpossible to conform the tray to the user's teeth. In view of theforegoing, “boil and bite” trays that do not have the tendency tocollapse and shrivel when heated generally do not accurately conform tothe user's teeth and are bulky and uncomfortable to wear.

Another alternative for teeth bleaching involves non-customized stripsof a flexible plastic material coated with a bleaching agent that can beapplied to the teeth. Such strips are placed against the teeth by theuser to cover the labial surface of the front 6 teeth. Such strips donot readily surround the dental arch, and are rather ineffective inholding the bleaching composition against the teeth. Because thestructure of the device is a simple strip that is initially flat, theyare awkward to place and may not hold the bleaching agent against theteeth long enough for a single treatment to have the desired effect.Frequent replacement and refitting of the strips is often required. Inaddition, they treat only the teeth at the front of the dental arch,they provide little or no treatment of the lingual surfaces of thetooth, and they do not provide adequate treatment to the margins betweenthe teeth. Finally, the upper and lower dental arches are typicallybleached individually. Trying to place separate strips over the upperand lower dental arches at the same time can be quite difficult.

Another alternative is a dual tray assembly as disclosed in U.S. Pat.No. 5,616,027 to Jacobs et al. The dual tray assembly is composed of anouter tray that supports or carries an inner tray made of athermoplastic material comprising EVA. In use, the tray assembly issubmerged in hot water, whereby the inner tray becomes pliable andmoldable and the outer tray remains rigid. The heated assembly is thenplaced in the mouth of the patient where the inner tray takes animpression of the patient's teeth. Thereafter, the assembly is removedfrom the patient's mouth and the inner tray is removed from the assemblyand trimmed so as to yield a customized tray that is thinner and morecomfortable to wear compared to conventional “boil and bite” trays.

In view of the foregoing, there is an ongoing need to developalternatives that are simpler to use but that result in acomfortable-fitting dental tray in order to promote compliance with aparticular treatment regimen.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to pre-shaped, non-custom dental traysthat are either preloaded with a dental treatment composition or filledwith a dental treatment composition just prior to placement over aperson's teeth. The pre-shaped dental trays are thin-walled so that theycan be placed over a person's teeth and/or gums and thereaftersubstantially conform to the person's teeth and/or gums without the needto formally customize the tray. The dental trays may be preloaded with adental treatment composition so as to yield a dental treatment devicethat is simple and easy to use.

The tray is preferably available in different configurations fortreatment of the upper and lower dental arches. Each tray is configuredso as to cover at least a portion of the teeth and/or gums of a dentalarch. Differences in the configurations of the upper and lower trays areintended to generally match the differences in a typical upper versuslower dental arch (e.g. the front surfaces of the front teeth of theupper arch are generally taller than the corresponding surfaces of theteeth of the lower arch). The pre-shaped dental trays are sufficientlyflexible so that they are able to conform to a wide variety ofdifferently-sized teeth and dental arches.

Each tray includes at least two walls that define a hollow interiorportion, or trough. According to one embodiment the tray includes abottom wall having a generally horseshoe shape, a front side wallextending laterally upward from a front side of the bottom wall, and arear side wall extending laterally upward from a rear side of the bottomwall. The bottom wall, front side wall, and rear side wall define ahollow interior, or trough, into which a dental treatment compositioncan be placed. The front and rear side walls may be parallel or flared,the latter providing a larger top opening than the width of the bottomwall.

The dental tray may also include a notch within the front side wall,preferably within an edge near the center of the front side wall, and/ora notch within the rear side wall, preferably within an edge near thecenter of the rear side wall. Such notches allow the tray to more easilyspread open and conform to larger-sized dental arches. In this way, thetray can be “one-size fits all” (or at least most).

The tray is formed of a thermoplastic elastomer, for example, low orultra low density polyethylene (LDPE or ULDPE), either alone or blendedwith one or more additional polymers, e.g., ethylene-vinyl acetatecopolymer (“EVA”), polycaprolactone (“PCL”), other types of polyethylene(“PE”), polypropylene (“PP”), or other plastic materials. LDPE, ULDPE,PE and PP are examples of polyolefins. Alternatively, the tray maycomprise one or more of ethylene vinyl acetate (EVA), polycaprolactone(PCL), or other thermoplastic materials. Plasticizers, flow additives,and fillers known in the art can be used as desired to modify theproperties of the material used to form the tray.

According to one embodiment, the tray is formed of a mixture of EVA andPP, comprising about 5 percent to about 35 percent polypropylene (PP),more preferably about 10 percent to about 30 percent polypropylene (PP),and most preferably about 15 percent to about 25 percent polypropylene(PP). The balance comprises ethylene-vinyl acetate (EVA), and optionallysmall quantities of additives.

The pre-shaped tray is generally thin-walled and flexible, with a wallthickness preferably in a range of about 0.05 mm to about 1 mm, morepreferably in a range of about 0.075 mm to about 0.75 mm, and mostpreferably in a range of about 0.1 mm to about 0.5 mm. The non-customtrays according to the invention are preferably sufficiently flexible sothat, when a pre-shaped tray is placed over a person's teeth, the traywill at least partially conform to the person's teeth during use. Inthis way, the pre-shaped, non-custom trays can approximate the comfortand fit of a customized dental tray.

According to one embodiment, the tray may be configured so as to coverthe occlusal, front, and rear surfaces of the teeth of the dental arch.In this way, both the front and rear surface of a person's teeth can betreated simultaneously. Optionally, the tray may be configured to coverportions of the gums for periodontal treatments. In one embodiment, thefront side wall of the dental tray may be contoured to approximatelycorrespond to the natural curvature of the labial and buccal surfaces ofa person's teeth in order to assist adhesion to teeth, particularly thecanines, which are typically more difficult to adhere to.

The tray is designed so that no heating of the tray or customization tothe person's teeth is required prior to use. Instead, the pre-shapedtray is designed so as to be used by simply placing a tray loaded with adental treatment composition over the person's teeth. Two trays canoptionally be used to treat the upper and lower dental archessimultaneously or the dental arches may be treated separately orsequentially.

In one embodiment, the dental tray is used with a dental bleachingcomposition. The bleaching composition preferably has a high enoughconcentration of bleaching agent to allow for substantially reduced weartime. A typical wear time is 30-60 minutes daily for five consecutivedays. The bleaching gel may include polyethylene glycol (PEG) orpropylene glycol (PPG), both of which can act either as thickeningagents or liquid carriers depending on their molecular weight, glycerin,carbamide peroxide or hydrogen peroxide, and other components. Otherthickening agents that may be used include polyvinyl pyrrolidone (PVP),carboxypolymethylene, carboxymethyl cellulose, and the like. PVP andcarboxypolymethylene have been found to be especially useful in makingtreatment compositions that are sticky and viscous.

The treatment compositions may contain other active agents in additionto, or instead of, the dental bleaching agent, e.g., antimicrobialagents (e.g. for a periodontal gum disorder treatment), anticariogenicagents, remineralizing agents, and the like. The treatment compositionsmay contain a thickening agent in order for the compositions to besufficiently thick so that, when the non-custom dental tray is placedover a person's teeth, the dental treatment composition will hold thetray against the person's teeth and allow the tray to at least partiallyconform to the person's teeth.

The trays of the present invention are useful for tooth bleaching orother dental treatments. When the tray is preloaded with a bleaching gelor other dental composition already preloaded in the tray, it can beapplied to a person's teeth and/or gums by simply placing the tray overthe person's teeth. Pre-loaded trays may be stored within a sealedpackaging container to protect the active agents and kept the dentaltrays clean prior to use. The tray may alternatively not be preloadedwith a treatment composition, allowing the user to fill the tray withany desired composition prior to insertion over the person's teeth.

The fact that the pre-shaped, non-custom dental tray does not requireheating or customization to the person's teeth makes it less expensiveand easier to use compared to boil and bite trays or trays that arecustomized using a stone model of the person's teeth. The inventivetrays can be sold over-the-counter for at-home use, reducing time andcost and eliminating any visits to a dental practitioner. Optionally,the tray may be provided as part of a dental bleaching kit containingone or more trays sized and configured for treatment of both the upperand lower dental arches, together with one or more dental treatmentcompositions, e.g., a bleaching gel.

These and other advantages and features of the present invention willbecome more fully apparent from the following description and appendedclaims, or may be learned by the practice of the invention as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by references to specific embodiments thereof, which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1A is a perspective view of an exemplary embodiment of apre-shaped, non-custom dental tray having a textured interior surfacethat is loaded with a dental treatment composition and configured forplacement over the upper dental arch;

FIG. 1B is a perspective view of an exemplary embodiment of apre-shaped, non-custom dental tray having a textured interior surfacethat is loaded with a dental treatment composition and configured forplacement over the lower dental arch;

FIG. 2A is a perspective view of an alternative embodiment of apre-shaped, non-custom dental tray having a dimpled interior surfacethat is loaded with a dental treatment composition and configured forplacement over the upper dental arch;

FIG. 2B is a perspective view of an alternative embodiment of apre-shaped, non-custom dental tray having a dimpled interior surfacethat is loaded with a dental treatment composition and configured forplacement over the lower dental arch;

FIG. 3 depicts a preloaded dental tray according to the invention thatis contoured to approximate the natural curvature of the labial andbuccal surfaces of a person's teeth;

FIG. 4 depicts a preloaded dental tray according to the invention thatis contained within a sealed packaging container;

FIG. 5 illustrates a person placing a dental tray according to theinvention over the upper dental arch; and

FIG. 6 illustrates a person placing a dental tray according to theinvention over the lower dental arch with a preloaded tray alreadyplaced over the upper dental arch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As summarized above, the present invention is directed to pre-shaped,non-custom dental trays that are either preloaded with a dentaltreatment composition or which can be filled with treatment compositionjust prior to use. The pre-shaped dental tray is a thin, soft,optionally clear, non-custom tray having sufficient structural integrityso that it can be easily placed over a person's teeth without anyexternal support structure. At the same time, the tray is sufficientlyflexible that it can approximately conform to the person's teeth withoutany prior heating of the tray or formal customization. At ambienttemperatures the tray is sufficiently thin and flexible so as to becomfortable-fitting.

In one embodiment, the pre-shaped dental tray is preloaded with a dentaltreatment composition, e.g., bleaching gel, making treatment simpler andeasier compared to existing dental treatment regimens. Because of itssimplicity and ease of use the tray may be sold over-the-counter forpeople wanting to whiten their own teeth, without the need for visits toa dental practitioner, resulting in a significantly less expensivealternative with good results.

The tray is preferably available in different configurations fortreatment of the upper and lower dental arches. The tray includes atleast two walls. According to one preferred embodiment, the trayincludes a front side wall, a rear side wall, and a bottom wall. Thetray is shaped to cover at least a portion of the rear surfaces of theteeth, the incisal edges, and especially the front surface of the teeth,which is the surface that is most often seen (and therefore mostdesirable to whiten). The trays may be configured to cover any desirednumber of teeth. In one embodiment, the trays may be sized andconfigured to cover at least 8 of the front upper teeth and at least 8of the front lower teeth, depending on the size of the tray, especiallythe tray's side walls, which provide treatment to the front and backsurfaces of the teeth. One advantage of using the pre-shaped dentaltrays according to the invention compared to bleaching strips is thatthe inventive dental trays according to the invention are better able toprovide a dental treatment composition that is able to flow into thespaces between the teeth. In this way, the margins between the teeth canbe better treated, e.g., bleached, compared to bleaching strips, whichonly reliably treat the front tooth surfaces and only if they are ableto remain in place and not become prematurely dislodged.

Referring now to the drawings, FIG. 1A illustrates an embodiment of apre-shaped, non-custom dental tray 100 configured for placement over aperson's upper dental arch. The dental tray 100 comprises a bottom wall102 having a generally horseshoe-shaped configuration generallyconforming to the size and shape of the person's upper dental arch. Thebottom wall 102 of the illustrated embodiment has a generally flatprofile, although it could have other shapes, as desired (e.g., curved).The dental tray 100 further includes a front side wall 104 extendinglaterally from a front end of the bottom wall 102 and a rear side wall106 extending laterally from a rear end: of the bottom wall 102.Together, the bottom wall 102, front side wall 104,-and rear side wall106 form a tray 100 that includes a hollow interior portion, or trough,that is open at the top, and that terminates at open ends 108.

The front side wall 104 of the tray 100 may extend substantiallyperpendicularly relative to the bottom wall 102, particularly at theends 108 of the tray, although it may extend at any desired angle so asto conform or correspond to a person's teeth in a desired manner. Thefront side wall 104 of the tray 100 is generally taller toward themiddle where it corresponds to the middle teeth and generally shortertoward the ends 108. Thus, the front side wall 104 tapers from front toback in order to approximately correspond to the descending height ofteeth from the middle of the dental arch (i.e., at the incisors) towardthe rear of the dental arch (i.e., at the molars).

In one embodiment, the front side wall 104 may include a notch 105. Thenotch 105 allows the tray to more easily spread open and conform tolarger dental arches compared to dental trays that do no include thisnotch. In this way, the pre-shaped dental trays according to theinvention can comfortably and effectively fit a larger range ofvaryingly-sized dental arches. The notch 105 is preferably formed nearthe middle portion 110, preferably at the top or edge of front side wall104. The rear side wall 106 may also include a notch 109 that is able tosubstantially perform the same function as notch 105.

In addition, front side wall 104 may be textured so as to include aplurality of indentations formed in the inside surface of walls 102,104, and 106. The plurality of indentations 107 may comprise a taffetatexture, tiny dimples, or a diamond grid texture, for example. In theembodiment illustrated in FIG. 1A, tray 100 includes a dense dimpletexture evenly distributed over the entire inside surface of walls 102,104, and 106 so as to provide multiple indentations adjacent to eachtooth. Including indentations 107 provides tiny reservoirs that are ableto hold additional quantities of a dental treatment composition, e.g., ableaching gel, against the surfaces of a person's teeth and/or gums.Indentations 107 can be incorporated in any/all of the walls, asdesired.

Like the front side wall 104, the rear side wall 106 of the tray 100 maybe shorter and substantially perpendicular to the bottom wall 102 at theends 108 of the horseshoe-shaped tray 100, but gradually open up to forma more oblique angle near a middle curved portion 110 of the tray so asto better accommodate the roof of the mouth near the middle portion 110of the tray 100. The height of the rear side wall 106 is generallyshorter than the corresponding section of the front side wall 104,particularly near the middle portion 110. This difference in height isto accommodate the differing height of the front versus the rear surfaceof the teeth in addition to the lower roof of the mouth relative to therear side wall 106.

The bottom wall 102 has a width near the curved middle portion 110 ofthe tray that is advantageously less than the width of the bottom wall102 between the middle portion 110 and the ends 108 of the tray 100.This allows for differences in the radial width of a person's incisorsand canines relative to the much wider bicuspids and molars.

In one embodiment, the upper edges of front side wall 104 and rear sidewall 106 are thickened and rounded. Rounding the edges of the trayprovides greater comfort for the wearer. Thickening the edges helps thetray maintain structural integrity.

The pre-shaped dental tray 100 can be used to hold and maintain a dentaltreatment composition against a person's teeth. FIG. 1A depicts a bead112 of a dental treatment composition that has been placed within thehollow interior portion, or trough, of the tray 100 adjacent to thefront wall 104 and bottom wall 102 of the tray 100. When placed over aperson's teeth, the bead 112 of the dental treatment composition willadvantageously spread over the front surfaces of the person's teeth, andwithin the spaces between the teeth.

According to one embodiment (illustrated in FIG. 1A), the bead 112 isplaced within the hollow interior, or trough, of the tray 100 adjacentto both the bottom wall 102 and the front wall 104. Bead 112 may beplaced and sized so as to rise about two-thirds of the height of frontwall 104. The dental treatment composition that forms bead 112 may forma dry skin over the composition, which aids in handling the tray 100 andbead 112.

FIG. 1B illustrates an embodiment of a pre-shaped dental tray 200configured for placement over a person's lower dental arch. The dentaltray 200 comprises a bottom wall having a generally horseshoe-shapedconfiguration generally conforming to the shape of the person's lowerdental arch. The bottom wall 202 has a generally flat planar profile,although it could have other shapes if desired (e.g., curved). Thedental tray 200 further includes a front side wall 204 extendinglaterally from a front end of the bottom wall 202 and a rear side wall206 extending laterally from a rear end of the bottom wall 202.Together, the bottom wall 202, front side wall 204, and rear side wall206 form a tray 200 that includes a hollow interior portion, or trough,that is open at the top, and that terminates at open ends 208.

The front side wall 204 of the tray 200 may extend substantiallyperpendicularly relative to the bottom wall 202, particularly at theends 208 of the tray, although it may extend at any desired angle so asto conform or correspond to a person's teeth in a desired manner. Thefront side wall 204 of the tray, 200 is generally taller toward themiddle where it corresponds to the middle teeth and generally shortertoward the ends 208. Thus, the front side wall 204 tapers from front to,back; in order to approximately correspond to the descending height ofteeth from the middle of the dental arch (i.e., at the incisors) towardthe rear of the dental arch (i.e., at the molars).

Front side wall 204 may also include a notch 205 and rear side wall 206may include a notch 209. The notches 205 and 209 function similar tonotches 105 and 109, respectively, allowing the tray to spread open andmore easily conform to larger-sized dental arches so as to comfortablyfit over any of a range-of variously sized dental arches. Notches 205and 209 are preferably formed near the middle portion 210, preferably atthe top of front side wall 204 and rear side wall 206, respectively.

The walls may be textured so as to include a plurality of indentations207 formed in the inside surface of front side wall 204, rear side wall206, and bottom wall 202. As shown in FIGS. 2A and 2B, indentations 207are evenly distributed over the entire inside surface of front side wall204 so as to provide multiple indentations adjacent to each tooth.Including indentations 207 provides tiny reservoirs that are able tohold additional quantities of a dental treatment composition, e.g., ableaching gel, against the front surfaces of a person's teeth.

Like the front side wall 204, the rear side wall 206 of the tray 200 isshort and substantially perpendicular to the bottom wall 202 at the ends208 of the horseshoe-shaped tray 200, but gradually opens up to form amore oblique angle near a middle curved portion 210 of the tray so as tobetter accommodate the floor of the mouth near the middle portion 210 ofthe tray 200. The upper edges of front side wall 204 and rear side wall206 may be thickened and rounded. Rounding the edges of the trayprovides greater comfort for the wearer. Thickening the edges helps thetray better maintain structural integrity. A bead 212 of a dentaltreatment composition, e.g., a bleaching gel, is shown in the hollowinterior portion, or trough, of the tray 200, adjacent to front sidewall 204.

The height of the rear side wall 206 may be somewhat shorter than thecorresponding section of the front side wall 204. This difference inheight is to accommodate the differing height of the front versus therear surface of the teeth in addition to the floor of the mouth relativeto the rear side wall 206. Both side walls 204 and 206 (especially frontside wall 204) are shorter than corresponding side walls 104 and 106because of the generally smaller size of the lower teeth versus theupper teeth. The bottom wall 202 has a width near the curved middleportion 210 of the tray that is advantageously less than the widthof-the bottom wall 202 between the middle portion 210 and the ends 208of the tray 200. This allows for the differences in the radial width ofa person's incisors and canines relative to the bicuspids and molars.

FIG. 2A illustrates an alternative embodiment of a pre-shaped,non-custom dental tray 100′ configured for placement over a person'supper dental arch. The dental tray 100′ comprises a bottom wall 102′ afront side wall 104′, and a rear side wall 106′. Together, the bottomwall 102′, front side wall 104′, and rear side wall 106′ form a tray100′ that includes a hollow interior portion, or trough, that is open atthe top, and that terminates at open ends 108′. The tray may includenotches 105′ and 109′. The tray 100′ is illustrated as having largerdimples 107′ formed in the inside surface of front side wall 104′. Inaddition, the bead of dental treatment composition 112′ lies in thehollow interior, or trough, of the tray 100′, adjacent to bottom wall102′.

FIG. 2B illustrates an embodiment of a pre-shaped dental tray 200′configured for placement over a person's lower dental arch. The dentaltray 200 comprises a bottom wall 202′, a front side wall 204′, and arear side wall 206′. Together, the bottom wall 202′, front side wall204′, and rear side wall 206′ form a tray 200′ that includes a hollowinterior portion, or trough, that is open at the top, and thatterminates at open ends 208′. The tray 200′ may include notches 205′ and209′. The tray 200′ is illustrated as having larger dimples 207′ formedin the inside surface of front side wall 204′. In addition, the bead ofdental treatment composition 212′ lies in the hollow interior portion,or trough, of the tray 200′, adjacent to bottom wall 202′.

FIG. 3 depicts an exemplary pre-shaped dental tray 300 that is contouredso to as approximately correspond to the natural curvature of a person'steeth, particularly the labial and buccal surfaces of the teeth. As inthe other trays depicted herein, the dental tray may include a bottomwall 302, a front side wall 304, and a rear side wall 306. Together, thebottom wall 302, front side wall 304, and rear side wall 306 form a tray300 that includes a hollow interior portion, or trough, that is open atthe top, and that terminates at open ends 308. The tray 300 mayoptionally include notches 305 and 309 near a middle portion 310. Thetray 300 is illustrated as having a textured surface and a dentaltreatment composition 312. In addition, the tray 300 includes contours307 that approximately correspond to the natural curvature of a person'steeth. The tray also optionally includes indentations 315 correspondingto the gingival between individual teeth.

Notwithstanding the foregoing, it should be understood that pre-shaped,non-customized dental trays within the scope of the invention can haveany desired configuration such that the trays of FIGS. 1-3 are merelyillustrative, non-limiting examples of pre-shaped dental traysconfigured for placement over the upper or lower dental arch.

The pre-shaped dental trays according to the invention can be made ofany appropriate polymeric material that is able to provide a thin andflexible tray. Exemplary materials include low density polyethylene(LDPE) and ultra-low density polyethylene (LDPE or ULDPE). Alternativematerials include ethylene-vinyl acetate copolymer (EVA) andpolycaprolactone (PCL). Each material can be used alone or incombination with other polymers, such as polypropylene (PP),ethylene-vinyl acetate copolymer (EVA), polycaprolactone (PCL), andother forms of polyethylene (PE). Flow additives, fillers, plasticizers,and the like may be added as desired. LDPE, ULDPE, PE and PP areexamples of polyolefins.

ULDPE refers to a range of-polyethylene-based copolymers defined ashaving a density of less than 0.914 g/cm3. LDPE is defined as having adensity in a range of 0.915-0.94 g/cm3. For purposes of comparison, highdensity polyethylene (HDPE) is defined as having a density in a range of0.94 to 0.97 g/cm3. Thus, LDPE and ULDPE can be readily distinguishedfrom other forms of PE by density, although other physical propertiesmay also differ in other respects, including water vapor transmissionrate, crystallinity, melting point, coefficient of linear expansion,elasticity modulus, yield strength, tensile strength, hardness, andimpact strength.

Any of various LDPE materials available from Dow Chemical may be used,as well as a number of ULDPE materials sold under the general trade nameAttane® by Dow Chemical. In general, Attane® refers to polyethylenecopolymers made from ethylene and octene. Specific examples includeAttane® 4201 (density=0.912 g/cm3), Attane® 4202 (density=0.913 g/cm3),Attane® 4203 (density=0.905 g/cm3), Attane® 4301 (density=0.914 g/cm3),and Attane® 4404 (density=0.904 g/cm3). Another suitable ULDPE materialis Exact® 4041 (density=0.878 g/cm3) made by Exxon-Mobil Chemical. Anexample of a suitable EVA material is Elvax® 250, available from DuPont.An example of a suitable PCL material is Capra® 650 from Solvoy-Interox.Other thermoplastic materials and blends used in making dental trays aredisclosed in U.S. Pat. No. 5,769,633 to Jacobs et al., U.S. Pat. No.5,051,476 to Uji et al., and U.S. Pat. No. 6,089,869 to Schwartz. Forpurposes of disclosing thermoplastic materials that can be made intodental trays, the foregoing patents are incorporated herein byreference.

According to one embodiment, the tray is formed of a mixture of EVA andPP, comprising about 5 percent to about 35 percent polypropylene (PP),more preferably about 10 percent to about 30 percent polypropylene (PP),and most preferably about 15 percent to about 25 percent polypropylene(PP). The balance comprises ethylene-vinyl acetate (EVA), and optionallysmall quantities of additives.

In one embodiment, the pre-shaped tray is formed by injection molding,although other manufacturing methods could be used. When forming thetray by injection molding, the thinness of the tray is limited by thedegree to which the tray material can be successfully injection molded.Another method for forming the inventive trays is thermal assistedvacuum forming in which a preformed sheet of polymeric material isvacuum formed over a template corresponding to the size and shape of thefinished dental tray. A punch die can be used to cut the finished trayfrom the excess sheet material.

In order for the inventive dental trays to have a desired level offlexibility, while also maintaining their ability to maintain theirshape as a tray prior to use, the at least two walls (e.g. bottom walls,front side walls, and rear side walls) preferably have a thickness in arange of about 0.05 mm to about 1 mm, more preferably in a range ofabout 0.075 mm to about 0.75 mm, and most preferably in a range of about0.1 mm to about 0.5 mm. The flexibility of the inventive dental traysallows them to at least partially conform to the person's teeth duringuse in order to approximate the comfort and fit of a custom dental traywithout the need to formally customize the tray. Moreover, because thetrays are not customized, the at least two side walls are substantiallydevoid of structures corresponding to the size and shape of a person'sunique dentition so that the dental tray is designed to fit over aplurality of differently-sized dental arches corresponding to differentpeople.

The dental trays according to the invention are useful for dentalbleaching or to provide other desired dental treatments (e.g., one ormore of antimicrobial, anticariogenic, remineralizing, and the like inaddition to, or instead of, dental bleaching). In use, the dental trayis either provided preloaded with a bleaching or other dentalcomposition, or a desired dental treatment composition is loaded intothe dental tray by the user. The dental tray is then placed over theperson's teeth to carry out a desired treatment regimen. The tray,coupled with the viscosity and stickiness of the dental treatmentcomposition, work together to hold and maintain the treatmentcomposition against the person's teeth. The non-customized dental traysaccording to the invention can be used once or repeatedly as desired.

Bleaching compositions used in combination with the dental treatmenttrays according to the present may advantageously be formulated so as toallow for substantially reduced treatment times as compared to typicalhome bleaching compositions, which are generally maintained in contactwith the person's teeth for up to 8 hours or more (e.g., overnight whilethe user is sleeping). In contrast, bleaching compositions can beformulated so as to be more potent so that they can provide effectivewhitening in 30-60 minutes, preferably when applied in 5-7 consecutivedaily treatments of 30-60 minutes each.

In one embodiment, the bleaching composition includes a bleaching agent,such as carbamide peroxide or hydrogen peroxide, or similar agents inconcentrations substantially above those commonly used forover-the-counter teeth whiteners. Subjecting the teeth to higherconcentrations of bleaching agent for a shorter period of time may, insome cases, cause less sensitivity in the teeth and less damage toadjacent tissues. By using higher concentrations of bleaching agent, thetime period required to whiten teeth to a satisfactory level is greatlyreduced.

When applying the bleaching gel compositions set forth herein it hasbeen found that a desired amount of whitening can be achieved by fiveconsecutive daily applications of no more than about 1 hour, whilesimultaneously having almost no sensitivity. Because of the shorttreatment time and lack of tooth sensitivity, the likelihood that usersof the composition will complete the treatment is increased, increasingthe probability of each user obtaining a desired degree of whitening.

A bleaching gel composition according to one embodiment includes, byweight: 16%-40% carbamide peroxide or 10%-20% hydrogen peroxide, 5-40%glycerin, 5-40% water, 10-60% polyethylene glycol (PEG) or polypropyleneglycol (PPG) as thickening agents, 0-5% flavor, and 0-5% sweetener.Instead of, or in addition to PEG and PPG, the dental bleaching gel mayinclude one or more of PVP, carboxypolymethylene, carboxymethylcellulose, other cellulose gums, fumed silica, and the like, astackifying agents useful in yielding a bleaching composition that ishighly viscous and sticky. The treatment compositions may also includeother active agents in addition to, or instead of, the dental bleachingagent, such as one or more desensitizing agents, anti-microbial agents,anti-tartar agents, anti-plaque agents, and remineralizing agents knownin the art. The treatment compositions may include EDTA as a stabilizingagent and/or sodium phosphate and phosphoric acid as buffers.

In the case where a dental treatment tray according to the invention ispre-loaded with a dental bleaching composition having a relatively highconcentration of a dental bleaching agent, or any other treatmentcompositions that may be less stable if exposed to air over time, it maybe desirable for such pre-loaded dental treatments to be stored within asealed packaging container prior to use. In this way, the treatmentcomposition can be shielded from excessive air, and the composition andtray can be kept clean for sanitary reasons prior to use. An example ofa sealed packaging container is depicted in FIG. 4, which depicts apre-loaded dental treatment tray according to the invention sealedwithin a plastic packet 450. The packet can be torn open and thepre-loaded tray removed just prior to use. In the alternative, thedental bleaching or other treatment compositions may be provided in aseparate container (e.g., a squeeze tube, not shown) and loaded into thedental tray by the user just prior to use.

FIG. 5 illustrates a preformed tray 100 (such as that illustrated inFIGS. 1A, 2A or 3) being placed by the user 514 over his or her upperdental arch. The tray is filled with a bleaching gel or other treatmentcomposition 112 (as seen in FIGS. 1A, 2A or 3), which was eitherpreloaded in the tray or placed in the tray just prior to use. The user314 is easily able to place the non-customized tray over the upperdental arch without heating the tray in order to conform it to theteeth, and there are no external or internal supports needed to supportthe tray prior to use. The elimination of these steps is a significantadvantage over other alternative trays because it makes use of the trayvery simple and easy. With more complicated alternatives, problems occurduring the heating and formation of the tray, which is a complexprocess, requiring the aid of a skilled dental practitioner to performthe customization of the tray correctly. The simplicity of thepre-formed non-customized tray of the present invention allows a userwanting to whiten his or her teeth to purchase the tray over the counterand perform the whitening treatment without the aid of a dentalpractitioner, resulting in a much less expensive tooth whiteningregimen.

FIG. 6 illustrates a tray 200 such as that illustrated in FIGS. 1B, 2Bor 3 being placed by the user 514 over his or her lower dental arch,optionally with the tray 100 as seen in FIG. 5 in place over the upperdental arch. The tray is filled with a bleaching gel or other treatmentcomposition (as seen in FIGS. 1B, 2B and 3), which was either preloadedin the tray or placed in the tray just prior to use. The user 514 iseasily able to place the pre-formed tray 200 over the lower dental arch,even while the tray 100 is in position over the upper dental arch. Thisis a further advantage of the invention, as it allows the person totreat both dental arches simultaneously, at low cost and with littleeffort.

The trays of the present invention may be provided as part of a dentalbleaching kit containing one or more trays for upper and lower dentalarches, and a bleaching gel and/or one or more other treatmentcompositions. Providing such a kit over-the-counter provides arelatively inexpensive alternative to people wanting to whiten their ownteeth compared to more expensive at-home bleaching regimens that requirethe formation of a customized dental tray (e.g., boil-and-bite or traysformed using a stone model of the person's teeth).

The dental bleaching or other treatment composition is preferablysufficiently thick and sticky so as to hold the dental treatment trayagainst the user's teeth, and also to cause the tray to at leastpartially conform to the user's teeth. In this way, the non-customdental trays according to the invention can be used to treat a widevariety of differently sized dental arches and teeth among differentusers without having to form a customized dental tray, as is commonlydone for home bleaching regimens. By conforming to a particular user'steeth, the dental trays according to the invention at least partiallyemulate a customized tray in terms of comfort and efficacy in holdingthe dental treatment composition against the user's teeth.

The following are several examples of suitable bleaching compositions.Such exemplary compositions are given by way of example, and not bylimitation, in order to illustrate dental bleaching compositions thathave been found to be useful when used to bleach a person's teeth usingthe inventive dental treatment trays according to the invention. Unlessotherwise indicated all percentages are by weight.

EXAMPLE 1

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Carbamide Peroxide 31% Glycerin (USP Kosher) 8% Water 8% PolyethyleneGlycol 20,000 49% Peach Flavor 2% Sodium Saccharin 2%

The resulting bleaching gel was easy to apply to the tray, was ofmoderate viscosity and was not so sticky that it could not be easilyremoved after the bleaching treatment by rinsing the user's mouth withwater. Additionally, the composition had a pleasant taste and showedpositive bleaching effects in a very short amount of time. Markedimprovements in tooth coloration occurred within five days. Use of thecomposition also did result in noticeable tooth sensitivity such as thatcommonly associated with other at-home bleaching compositions thatutilize carbamide peroxide even though the composition had approximatelythree times the amount of carbamide peroxide found in conventionalat-home whitening kits.

EXAMPLE 2

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Carbamide Peroxide 26% Glycerin (USP Kosher) 12% Water   6%,Polyethylene Glycol 20,000 55% Sodium Saccharin  1%

While the bleaching gel composition in Example 2 whitens teeth well, itdid not taste as well as the dental bleaching composition made accordingto Example 1.

EXAMPLE 3

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Carboxymethylcellulose (Na+ salt)   2% Carbamide Peroxide 22.5% Glycerin(USP Kosher)   28% Water 16.4% Sodium Saccharin (powder)   2% SodiumEDTA  0.1% Cabosil M-5 (fumed silica)   7% Peach Flavor   2%Polyethylene Glycol 20,000   20%

The resulting bleaching gel was easy to apply to the tray, was ofmoderate viscosity and was not so sticky that it could not be easilyremoved after the bleaching treatment by rinsing the user's mouth withwater. Additionally, the composition had a pleasant taste and showedpositive bleaching effects in a very short amount of time. Markedimprovements in tooth coloration occurred within five days. Use of thecomposition also did result in noticeable tooth sensitivity such as thatcommonly associated with other at-home bleaching compositions thatutilize carbamide peroxide even though the composition had approximatelythree times the amount of carbamide peroxide found in conventionalat-home whitening kits.

EXAMPLE 4

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Carbamide Peroxide 35% Glycerin (USP Kosher) 7% Water 9% PolyethyleneGlycol 10,000 44% wintergreen flavor 2% Sodium Saccharin 3%

EXAMPLE 5

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Hydrogen Peroxide 12% Glycerin (USP Kosher) 18% Water 13% PolyethyleneGlycol 20,000 50% Peach Flavor 4% Sodium Saccharin 3%

The resulting composition was easy to apply and provided positivebleaching effects in a relatively short time frame, as discussed above.

EXAMPLE 6

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Hydrogen Peroxide 19% Glycerin (USP Kosher) 14% Water 8% PolyethyleneGlycol 20,000 56% Sodium Saccharin 3%

EXAMPLE 7

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Hydrogen Peroxide 18% Glycerin (USP Kosher) 10% Water 13% PolyethyleneGlycol 10,000 50% Wintergreen Flavor 5% Sodium Saccharin 4%

For each application, the tray is either preloaded with the bleachinggel or filled just a prior to insertion into the user's mouth. Becauseof the high level of carbamide peroxide or hydrogen peroxide, the trayis preferably kept in the mouth for less than about one hour. Byproviding the correct balance of viscosity and stickiness of thecomposition, the vast majority (i.e., more than about 90%) of thecomposition can easily be removed from the user's teeth within an hoursimply by effervescence and the saliva in the user's mouth. This is animprovement over many existing teeth whitening compositions which areused for eight to twelve hours and which include materials designed tokeep the composition on the user's teeth for a prolonged period. Thecompositions adhere to the user's teeth for prolonged periods asintended, but must sometimes be removed by brushing.

EXAMPLE 8

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Carboxy Methyl Cellulose (sodium salt)   2% Carbamide Peroxide 22.5%Glycerin   28% Water 16.4% Sodium Saccharine Powder   2% Sodium EDTA 0.1% Cabosil M-5 (SiO₂)   7% Peach Flavor   2% Polyethylene Glycol(M.W. = 20,000)   20%

The resulting dental bleaching gel was placed within a flexible,thin-walled dental tray and then placed over a person's teeth. Becausethe bleaching gel was sticky and viscous it was able to adhere andretain the flexible, thin-walled dental tray reasonably well against theperson's teeth for a desired period of time (e.g., 1 hour or more).

EXAMPLE 9

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Water 19.2% Edetate Disodium  0.1% Carbamide Peroxide 18.5% Xylitol C  7% Glycerin 25.4% CARBOPOL 974  5.3% NaOH (50% in water)  4.5% CarboxyMethyl Cellulose   4% Kollidon 90F   10% Peach Flavor   3% Sucralose(25% in water)   3%

The resulting dental bleaching gel was extremely thick. The resultingdental bleaching gel was placed within a flexible, thin-walled dentaltray and then placed over a person's teeth. Because the bleaching gelwas sticky and viscous it was able to adhere and retain the flexible,thin-walled dental tray reasonably well against the person's teeth for adesired period of time (e.g., 1 hour or more).

EXAMPLE 10

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Water   18% Edetate Disodium  0.1% Carbamide Peroxide 18.5% Sucralose(25% in water)   3% Glycerin 41.6% CARBOPOL 974  5.3% NaOH (50% inwater)  4.5% Kollidon 90F   2% Carboxy Methyl Cellulose   4% PeachFlavor   3%

The resulting dental bleaching gel was placed within a flexible,thin-walled dental tray and then placed over a person's teeth. Becausethe bleaching gel was sticky and viscous it was able to adhere andretain the flexible, thin-walled dental tray reasonably well against theperson's teeth for a desired period of time (e.g., 1 hour or more).

EXAMPLE 11

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Water   18% EDTA  0.1% Carbamide Peroxide   22% Sucralose (25% in water)  2% Glycerin 37.1% CARBOPOL 974  5.3% NaOH (50% in water)  4.5%Kollidon 90F   2% Carboxy Methyl Cellulose   5% Peach Flavor   4%

The resulting dental bleaching gel was placed within a flexible,thin-walled dental tray and then placed over a person's teeth. Becausethe bleaching gel was sticky and viscous it was able to adhere andretain the flexible, thin-walled dental tray reasonably well against theperson's teeth for a desired period of time (e.g., 1 hour or more).

EXAMPLE 12

A dental bleaching composition suitable for use in combination with thedental trays disclosed herein was formed by mixing together thefollowing components:

Water   18% EDTA  0.1% Carbamide Peroxide   22% Sucralose (25% in water)  2% Glycerin 40.1% CARBOPOL 974  5.3% NaOH (50% in water)  4.5%Kollidon 90F   2% Carboxy Methyl Cellulose   5% Peppermint Oil   1%

The resulting dental bleaching gel was placed within a flexible,thin-walled dental tray and then placed over a person's teeth. Becausethe bleaching gel was sticky and viscous it was able to adhere andretain the flexible, thin-walled dental tray reasonably well against theperson's teeth for a desired period of time (e.g. 1 hour or more).

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended, claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A pre-shaped, non-custom dental tray suitable for placement over atleast a portion of one of a person's upper or lower dental arches,wherein the dental tray comprises at least one type of polymericmaterial, the dental tray further comprising: at least two wallsdefining a hollow interior portion therebetween, wherein an entireinterior surface of at least one of the walls includes a plurality ofspaced-apart indentations therein for holding a treatment compositionagainst a person's teeth when the dental tray is in use, thespaced-apart indentations being substantially evenly distributed acrossthe entire interior surface of the at least one of the walls and so asto provide multiple indentations adjacent to each tooth when the dentaltray is in use, wherein the dental tray is substantially devoid ofstructures corresponding to the size and shape of a person's uniquedentition so that the dental tray is designed to comfortably fit over aplurality of differently-sized dental arches corresponding to differentpeople, wherein the dental tray has a maximum wall thickness of lessthan about 1 mm in order to be flexible across its entirety so that,when the non-custom dental tray is placed over a person's teeth, theentire tray can flex and thereby at least partially conform to theperson's teeth during use in order to approximate the comfort and fit ofa custom dental tray without the need to formally customize the tray. 2.A pre-shaped, non-custom dental tray as defined in claim 1, wherein theat least two walls include a front side wall, a rear side wall, and abottom wall interconnecting the front and rear side walls, wherein thefront side wall, rear side wall and bottom wall each have asubstantially uniform wall thickness of less than about 1 mm.
 3. Apre-shaped, non-custom dental tray as defined in claim 1, wherein thespaced-apart indentations comprise at least one of a taffeta texture,tiny dimples, or a diamond grid texture.
 4. A pre-shaped, non-customdental tray as defined in claim 1, wherein the dental tray is formedfrom a mixture comprising ethylene vinyl acetate (EVA) and polypropylene(PP).
 5. A pre-shaped, non-custom dental tray as defined in claim 4,wherein the mixture comprises from about 10% to about 30% by weight PP,with the balance consisting essentially of EVA.
 6. A pre-shaped,non-custom dental tray as defined in claim 4, wherein the mixturecomprises from about 15% to about 25% by weight PP, with the balanceconsisting essentially of EVA.
 7. A pre-shaped, non-custom dental trayas defined in claim 1, wherein the dental tray has a maximum thicknessof less than about 0.75 mm.
 8. A pre-shaped, non-custom dental tray asdefined in claim 1, wherein the dental tray has a maximum thickness ofless than about 0.5 mm.
 9. A pre-shaped, non-custom dental tray asdefined in claim 1, wherein the dental tray is sized and configured soas to approximately terminate at or near a person's gingival margin whenthe dental tray is placed over the person's teeth.
 10. A pre-shaped,non-custom dental tray suitable for placement over at least a portion ofone of a person's upper or lower dental arches, wherein the dental traycomprises at least one type of polymeric material, the dental trayfurther comprising: at least two walls defining a hollow interiorportion therebetween, wherein an entire interior surface of at least oneof the walls includes a plurality of spaced-apart indentations formedtherein and substantially evenly distributed over the entire interiorsurface of the at least two walls, the spaced-apart indentations beingarranged so as to provide multiple indentations adjacent to each toothwhen the dental tray is in use and so as to form at least one of ataffeta texture, evenly distributed tiny dimples, or a diamond gridtexture for holding a treatment composition against a person's teethwhen the dental tray is in use, wherein the dental tray is substantiallydevoid of structures corresponding to the size and shape of a person'sunique dentition so that the dental tray is designed to comfortably fitover a plurality of differently-sized dental arches corresponding todifferent people, wherein the dental tray has a maximum wall thicknessof less than about 1 mm in order to be flexible across its entirety sothat, when the non-custom dental tray is placed over a person's teeth,the entire tray can at least partially conform to the person's teethduring use in order to approximate the comfort and fit of a customdental tray without the need to formally customize the tray.
 11. Amethod of treating a person's teeth, comprising: providing a non-customdental tray according to claims 1, or 10; placing a dental treatmentcomposition into the hollow interior portion of the dental tray; andpositioning the dental tray over the person's teeth in order to contactthe teeth with the treatment composition.